NeXT, Inc. was an American computer and software company founded in 1985 by Apple Computer co-founder Steve Jobs. Its name was pronounced as "Next". Based in Redwood City, the company developed and manufactured a series of computer workstations intended for the higher education and business markets. NeXT was founded by Jobs. NeXT introduced the first NeXT Computer in 1988, the smaller NeXTstation in 1990; the NeXT computers experienced limited sales, with estimates of about 50,000 units shipped in total. Their innovative object-oriented NeXTSTEP operating system and development environment were influential; the first major outside investment was from Ross Perot, who invested after seeing a segment about NeXT on The Entrepreneurs. In 1987, he invested $20 million in exchange for 16 percent of NeXT's stock and subsequently joined the board of directors in 1988. NeXT released much of the NeXTSTEP system as a programming environment standard called OpenStep. NeXT withdrew from the hardware business in 1993 to concentrate on marketing OPENSTEP for Mach, its own OpenStep implementation, for several original equipment manufacturers.
NeXT developed WebObjects, one of the first enterprise web application frameworks. WebObjects never became popular because of its initial high price of $50,000, but it remains a prominent early example of a Web server based on dynamic page generation rather than on static content. Apple purchased NeXT in 1997 for $429 million, 1.5 million shares of Apple stock. As part of the agreement, Steve Jobs, Chairman and CEO of NeXT Software, returned to Apple, the company he co-founded in 1976; the founder promised to merge software from NeXT with Apple's hardware platforms resulting in macOS, iOS, watchOS, tvOS. These operating systems are based upon the NeXTSTEP and OPENSTEP foundation. In 1985, Apple co-founder Steve Jobs led Apple's SuperMicro division, responsible for the development of the Macintosh and Lisa personal computers; the Macintosh had been successful on university campuses because of the Apple University Consortium, which allowed students and institutions to buy the computers at a discount.
The consortium had earned more than $50 million on computers by February 1984. While chairman, Jobs visited university departments and faculty members to sell Macintosh. Jobs met Paul Berg, a Nobel Laureate in chemistry, at a luncheon held in Silicon Valley to honor François Mitterrand President of France. Berg was frustrated by the expense of teaching students about recombinant DNA from textbooks instead of in wet laboratories, used for the testing and analysis of chemicals and other materials or biological matter. Wet labs were prohibitively expensive for lower-level courses and were too complex to be simulated on personal computers of the time. Berg suggested to Jobs to use his influence at Apple to create a "3M computer" workstation for higher education, featuring at least one megabyte of random-access memory, a megapixel display and megaFLOPs performance, hence the name "3M". Jobs was intrigued by Berg's concept of a workstation and contemplated starting a higher education computer company in the fall of 1985, amidst increasing turmoil at Apple.
Jobs' division did not release upgraded versions of the Macintosh and much of the Macintosh Office system. As a result, sales plummeted, Apple was forced to write off millions of dollars in unsold inventory. Apple's chief executive officer John Sculley ousted Jobs from his day-to-day role at Apple, replacing him with Jean-Louis Gassée in 1985; that year, Jobs began a power struggle to regain control of the company. The board of directors sided with Sculley while Jobs took a business visit to Western Europe and the Soviet Union on behalf of Apple. After several months of being sidelined, Jobs resigned from Apple on September 13, 1985, he told the board he was leaving to set up a new computer company, that he would be taking several Apple employees from the SuperMicro division with him. He told the board that his new company would not compete with Apple and might consider licensing its designs back to them to market under the Macintosh brand. Jobs named his new company Next, Inc. A number of former Apple employees followed him to Next, including Joanna Hoffman, Bud Tribble, George Crow, Rich Page, Susan Barnes, Susan Kare, Dan'l Lewin.
After consulting with major educational buyers from around the country, including a follow-up meeting with Paul Berg, a tentative specification for the workstation was drawn up. It was designed to be powerful enough to run wet lab simulations and cheap enough for college students to use in their dormitory rooms. Before the specifications were finished, Apple sued Next for "nefarious schemes" to take advantage of the cofounders' insider information. Jobs remarked, "It is hard to think that a $2 billion company with 4,300-plus people couldn't compete with six people in blue jeans." The suit was dismissed before trial. In 1986, Jobs recruited the famous graphic designer Paul Rand to create a brand identity costing $100,000. Jobs recalled, "I asked him if he would come up with a few options, he said,'No, I will solve your problem for you and you will pay me. You don’t have to use the solution. If you want options go talk to other people.'" Rand created a 20-page brochure detailing the brand, including the precise angle used for the logo and a new company name spelling, NeXT.
NeXT changed its business plan in mid-1986. The company decided to develop both computer hardware and software, instead of just a low-end workstation
A floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, multiplication, square root, bitshifting; some systems can perform various transcendental functions such as exponential or trigonometric calculations, though in most modern processors these are done with software library routines. In general purpose computer architectures, one or more FPUs may be integrated as execution units within the central processing unit; when a CPU is executing a program that calls for a floating-point operation, there are three ways to carry it out: A floating-point unit emulator Add-on FPU Integrated FPU Historically systems implemented floating point via a coprocessor rather than as an integrated unit. This could be an entire circuit board or a cabinet. Where floating-point calculation hardware has not been provided, floating point calculations are done in software, which takes more processor time but which avoids the cost of the extra hardware.
For a particular computer architecture, the floating point unit instructions may be emulated by a library of software functions. Emulation can be implemented on any of several levels: in the CPU as microcode, as an operating system function, or in user space code; when only integer functionality is available the CORDIC floating point emulation methods are most used. In most modern computer architectures, there is some division of floating-point operations from integer operations; this division varies by architecture. CORDIC routines has been implemented in the Intel 8087, 80287, 80387 up to the 80486 coprocessor series as well as in the Motorola 68881 and 68882 for some kinds of floating-point instructions as a way to reduce the gate counts of the FPU sub-system. Floating-point operations are pipelined. In earlier superscalar architectures without general out-of-order execution, floating-point operations were sometimes pipelined separately from integer operations. Since the early 1990s, many microprocessors for desktops and servers have more than one FPU.
The modular architecture of Bulldozer microarchitecture uses a special FPU named FlexFPU, which uses simultaneous multithreading. Each physical integer core, two per module, is single threaded, in contrast with Intel's Hyperthreading, where two virtual simultaneous threads share the resources of a single physical core; some floating-point hardware only supports the simplest operations – addition and multiplication. But the most complex floating-point hardware has a finite number of operations it can support – for example, none of them directly support arbitrary-precision arithmetic; when a CPU is executing a program that calls for a floating-point operation, not directly supported by the hardware, the CPU uses a series of simpler floating-point operations. In systems without any floating-point hardware, the CPU emulates it using a series of simpler fixed-point arithmetic operations that run on the integer arithmetic logic unit; the software that lists the necessary series of operations to emulate floating-point operations is packaged in a floating-point library.
In some cases, FPUs may be specialized, divided between simpler floating-point operations and more complicated operations, like division. In some cases, only the simple operations may be implemented in hardware or microcode, while the more complex operations are implemented as software. In some current architectures, the FPU functionality is combined with units to perform SIMD computation. In the 1980s, it was common in IBM PC/compatible microcomputers for the FPU to be separate from the CPU, sold as an optional add-on, it would only be purchased if needed to enable math-intensive programs. The IBM PC, XT, most compatibles based on the 8088 or 8086 had a socket for the optional 8087 coprocessor; the AT and 80286-based systems were socketed for the 80287, 80386/80386SX based machines for the 80387 and 80387SX although early ones were socketed for the 80287, since the 80387 did not exist yet. Other companies manufactured co-processors for the Intel x86 series; these included Weitek. Coprocessors were available for the Motorola 68000 family, the 68881 and 68882.
These were common in Motorola 68020/68030-based workstations like the Sun 3 series. They were commonly added to higher-end models of Apple Macintosh and Commodore Amiga series, but unlike IBM PC-compatible systems, sockets for adding the coprocessor were not as common in lower end systems. There are add-on FPUs coprocessor units for microcontroller units /single-board computer, which serve to provide floating-point arithmetic capability; these add-on FPUs are host-processor-independent, possess their own programming requirements and are pro
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution. It was the first open-source BSD descendant released after 386BSD was forked, it continues to be developed and is available for many platforms, including servers, handheld devices, embedded systems. The NetBSD project focuses on code clarity, careful design, portability across many computer architectures, its source code is permissively licensed. NetBSD was derived from the 4.3BSD-Reno release of the Berkeley Software Distribution from the Computer Systems Research Group of the University of California, via their Net/2 source code release and the 386BSD project. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development; the four founders of the NetBSD project, Chris Demetriou, Theo de Raadt, Adam Glass, Charles Hannum, felt that a more open development model would benefit the project: one centered on portable, correct code.
They aimed to produce a multi-platform, production-quality, BSD-based operating system. The name "NetBSD" was suggested by De Raadt, based on the importance and growth of networks such as the Internet at that time, the distributed, collaborative nature of its development; the NetBSD source code repository was established on 21 March 1993 and the first official release, NetBSD 0.8, was made on 19 April 1993. This was derived from 386BSD 0.1 plus the version 0.2.2 unofficial patchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, various other improvements. The first multi-platform release, NetBSD 1.0, was made in October 1994, being updated with 4.4BSD-Lite sources, it was free of all encumbered 4.3BSD Net/2 code. In 1994, for disputed reasons, one of the founders, Theo de Raadt, was removed from the project, he founded a new project, OpenBSD, from a forked version of NetBSD 1.0 near the end of 1995. In 1998, NetBSD 1.3 introduced the pkgsrc packages collection.
Until 2004, NetBSD 1.x releases were made at annual intervals, with minor "patch" releases in between. From release 2.0 onwards, NetBSD uses semantic versioning, each major NetBSD release corresponds to an incremented major version number, i.e. the major releases following 2.0 are 3.0, 4.0 and so on. The previous minor releases are now divided into two categories: x.y "stable" maintenance releases and x.y.z releases containing only security and critical fixes. As the project's motto suggests, NetBSD has been ported to a large number of 32- and 64-bit architectures; these range from VAX minicomputers to Pocket PC PDAs. As of 2009, NetBSD supports 57 hardware platforms; the kernel and userland for these platforms are all built from a central unified source-code tree managed by CVS. Unlike other kernels such as μClinux, the NetBSD kernel requires the presence of an MMU in any given target architecture. NetBSD's portability is aided by the use of hardware abstraction layer interfaces for low-level hardware access such as bus input/output or DMA.
Using this portability layer, device drivers can be split into "machine-independent" and "machine-dependent" components. This makes a single driver usable on several platforms by hiding hardware access details, reduces the work to port it to a new system; this permits a particular device driver for a PCI card to work without modifications, whether it is in a PCI slot on an IA-32, PowerPC, SPARC, or other architecture with a PCI bus. A single driver for a specific device can operate via several different buses, like ISA, PCI, or PC Card. In comparison, Linux device driver code must be reworked for each new architecture; as a consequence, in porting efforts by NetBSD and Linux developers, NetBSD has taken much less time to port to new hardware. This platform independence aids the development of embedded systems since NetBSD 1.6, when the entire toolchain of compilers, assemblers and other tools support cross-compiling. In 2005, as a demonstration of NetBSD's portability and suitability for embedded applications, Technologic Systems, a vendor of embedded systems hardware and demonstrated a NetBSD-powered kitchen toaster.
Commercial ports to embedded platforms, including the AMD Geode LX800, Freescale PowerQUICC processors, Marvell Orion, AMCC 405 family of PowerPC processors, Intel XScale IOP and IXP series, were available from and supported by Wasabi Systems. The NetBSD cross-compiling framework lets a developer build a complete NetBSD system for an architecture from a more powerful system of different architecture, including on a different operating system. Several embedded systems using NetBSD have required no additional software development other than toolchain and target rehost. NetBSD features pkgsrc, a framework for building and managing third-party application software packages; the pkgsrc collection consists of more than 18,000 packages as of April 2018. Building and installing packages such as KDE, GNOME, the Apache HTTP Server or Perl is performed through the use of a system of makefiles; this can automatically fetch the source code, patch, configure and install the package such that it can be removed again later.
An alternative to compiling from source is to use a precompiled binary package. In either case, any prerequisites/dependencies will be installed automatically by the package system, without need for manual intervention. Pkgsrc supports not only NetBSD, but several other BSD variants like
Digital signal processor
A digital signal processor is a specialized microprocessor, with its architecture optimized for the operational needs of digital signal processing. The goal of DSP is to measure, filter or compress continuous real-world analog signals. Most general-purpose microprocessors can execute digital signal processing algorithms but may not be able to keep up with such processing continuously in real-time. Dedicated DSPs have better power efficiency, thus they are more suitable in portable devices such as mobile phones because of power consumption constraints. DSPs use special memory architectures that are able to fetch multiple data or instructions at the same time. Digital signal processing algorithms require a large number of mathematical operations to be performed and on a series of data samples. Signals are converted from analog to digital, manipulated digitally, converted back to analog form. Many DSP applications have constraints on latency. Most general-purpose microprocessors and operating systems can execute DSP algorithms but are not suitable for use in portable devices such as mobile phones and PDAs because of power efficiency constraints.
A specialized digital signal processor, will tend to provide a lower-cost solution, with better performance, lower latency, no requirements for specialised cooling or large batteries. Such performance improvements have led to the introduction of digital signal processing in commercial communications satellites where hundreds or thousands of analog filters, frequency converters and so on are required to receive and process the uplinked signals and ready them for downlinking, can be replaced with specialised DSPs with a significant benefits to the satellites' weight, power consumption, complexity/cost of construction and flexibility of operation. For example, the SES-12 and SES-14 satellites from operator SES, both intended for launch in 2017, were built by Airbus Defence and Space with 25% of capacity using DSP; the architecture of a digital signal processor is optimized for digital signal processing. Most support some of the features as an applications processor or microcontroller, since signal processing is the only task of a system.
Some useful features for optimizing DSP algorithms are outlined below. By the standards of general-purpose processors, DSP instruction sets are highly irregular. Both traditional and DSP-optimized instruction sets are able to compute any arbitrary operation but an operation that might require multiple ARM or x86 instructions to compute might require only one instruction in a DSP optimized instruction set. One implication for software architecture is that hand-optimized assembly-code routines are packaged into libraries for re-use, instead of relying on advanced compiler technologies to handle essential algorithms. With modern compiler optimizations hand-optimized assembly code is more efficient and many common algorithms involved in DSP calculations are hand-written in order to take full advantage of the architectural optimizations. Multiply–accumulates operations used extensively in all kinds of matrix operations convolution for filtering dot product polynomial evaluation Fundamental DSP algorithms depend on multiply–accumulate performance FIR filters Fast Fourier transform Instructions to increase parallelism: SIMD VLIW superscalar architecture Specialized instructions for modulo addressing in ring buffers and bit-reversed addressing mode for FFT cross-referencing Digital signal processors sometimes use time-stationary encoding to simplify hardware and increase coding efficiency.
Multiple arithmetic units may require memory architectures to support several accesses per instruction cycle Special loop controls, such as architectural support for executing a few instruction words in a tight loop without overhead for instruction fetches or exit testing Saturation arithmetic, in which operations that produce overflows will accumulate at the maximum values that the register can hold rather than wrapping around. Sometimes various sticky bits operation modes are available. Fixed-point arithmetic is used to speed up arithmetic processing Single-cycle operations to increase the benefits of pipelining Floating-point unit integrated directly into the datapath Pipelined architecture Highly parallel multiplier–accumulators Hardware-controlled looping, to reduce or eliminate the overhead required for looping operations In engineering, hardware architecture refers to the identification of a system's physical components and their interrelationships; this description called a hardware design model, allows hardware designers to understand how their components fit into a system architecture and provides to software component designers important information needed for software development and integration.
Clear definition of a hardware architecture allows the various traditional engineering disciplines to work more together to develop and manufacture new machines and components. Hardware is als
John Patrick Crecine
John Patrick "Pat" Crecine was an American educator and economist who served as President of Georgia Tech, Dean at Carnegie Mellon University, business executive, professor. After receiving his early education at public schools in Lansing, Michigan, he earned a bachelor's degree in industrial management, master's and doctoral degrees in industrial administration from the Graduate School of Industrial Administration at Carnegie Mellon University, he spent a year at the Stanford University School of Business. Dr. Crecine's academic career began at the University of Michigan, where he established the country's first graduate program in public policy in 1968 as the first Director of the Institute of Public Policy Studies, IPPS, while holding academic appointments in political science and sociology. While at Michigan, Crecine established a joint Law and Public Policy program with the Michigan Law School and joint Ph. D. programs with Economics, Political Science, Sociology and Regional Planning, Industrial Engineering, each of which were represented in the core curriculum of the IPPS Masters Program.
While at Michigan, he interrupted his teaching several times to serve the federal government as an economist and consultant, to work as an economist with the RAND Corporation. He earned tenure in 1968 and full professorships in Political Science and Sociology in 1970. In 1976, he became dean Carnegie Mellon's Dietrich College of Humanities and Social Sciences and Professor of Political Economy in the Department of Social and Decision Sciences and in the School of Urban and Public Affairs; as Dean he conceived of and implemented a core curriculum, described by the Education Editor of the New York Times as "the most innovative in America," and added departments of Statistics and Decision Sciences and several research centers in the cognitive sciences and computational linguistics to the College. Following a year as Visiting Fellow Commoner at Cambridge University, he was appointed Senior Vice President and Provost in 1983, with administrative responsibility for Carnegie Mellon's academic and systems development in computing Andrew Project and computer science and initiated, with Prof. Raj Reddy, the formation of the Carnegie Mellon School of Computer Science.
He was the founding chief executive officer of the Inter-university Consortium for Educational Computing, an association of research universities. In 1986, he was the first chief administrative officer and oversaw the founding of the University Athletic Association, an NCAA Division III Conference. Crecine returned to Carnegie Mellon in the fall of 2006 as Distinguished Service Professor at the Heinz College. In 1987, Dr. Crecine became the ninth president of the Georgia Institute of Technology. In addition to his administrative responsibilities, Dr. Crecine held a joint appointment as tenured professor in the new School of International Affairs, the School of Industrial and Systems Engineering. During his tenure, he initiated the establishment of three new colleges at Tech: the College of Computing, he served as Chairman of the Georgia Tech Athletic Association and as President of the Georgia Tech Research Corporation. During his tenure as President, the College of Engineering's ranking climbed from 14th to 9th in the country, the institution was transformed from a specialized institution to a top-30 national university, SAT scores of Fall entering freshmen for 1992, 1993, 1994 rose to become the highest of any public research university in the U.
S. graduation rates increased by nearly 12 percent, student facilities and housing were doubled from those of the previous 102 years of the institution’s existence, sponsored research awards more than doubled. During Crecine's tenure at Georgia Tech, African American student enrollment doubled at undergraduate and graduate levels, academic performance at the undergraduate level exceeded majority student performance, with 40% of freshman African American students making the Dean's list, with most African American students enrolling in demanding engineering programs. Graduate Ph. D. production for minority students in engineering now approached that of the rest of the nation, combined. Numbers of tenure-track minority faculty tripled and female faculty doubled. During Crecine's tenure and under Athletic Director Homer Rice's leadership, Georgia Tech’s intercollegiate athletic programs thrived with the football team winning the NCAA national championship in 1990, the basketball team going to the NCAA "Final Four" in 1990 along with several ACC championships, the baseball team going to the 1994 College World Series.
During Dr. Crecine's tenure, Georgia Tech student-athletes had the same graduation rates as other Georgia Tech students. During 1989-92, he chaired the Office of Technology Assessment's Networking and High Performance Computing Panel, which led to the National Research and Education Network Act and the establishment of the first publicly deployed Internet. In November 1987, Dr. Crecine, acting on behalf of Georgia Tech, volunteered to help Atlanta become the host city for the 1996 Centennial Olympic Games and was an active member of the Atlanta Committee for the Olympic Games before and after Atlanta was chosen as host for the Centennial Games. Dr. Crecine conceived of and arranged funding for the development of a computerized, virtual re
The NeXTcube Turbo was a high-end workstation computer developed and sold by NeXT. It superseded the earlier NeXTcube workstation and was housed in the same cube-shaped magnesium enclosure; the workstation ran the NeXTSTEP operating system. The NeXTcube Turbo was a development of the earlier NeXTcube, it differed from its predecessor in having a 33 MHz 68040 processor. The NeXTdimension board could be used in the NeXTcube Turbo. There was a rare accelerator board known as the Nitro, it increased the speed of a NeXTcube Turbo by replacing the standard 33 MHz processor with a 40 MHz one. Complete Nitro systems are traded. Display: 1120×832 17" grayscale Operating System: NeXTstep, OpenStep CPU: 33 MHz 68040 with integrated floating-point unit Digital Signal Processor: Motorola DSP56001 Size: 12" × 12" × 12" NeXT Computer NeXTcube NeXTstation NeXT character set old-computers.com — NeXTcube NeXTComputers.org
Apple Inc. is an American multinational technology company headquartered in Cupertino, that designs and sells consumer electronics, computer software, online services. It is considered one of the Big Four of technology along with Amazon and Facebook; the company's hardware products include the iPhone smartphone, the iPad tablet computer, the Mac personal computer, the iPod portable media player, the Apple Watch smartwatch, the Apple TV digital media player, the HomePod smart speaker. Apple's software includes the macOS and iOS operating systems, the iTunes media player, the Safari web browser, the iLife and iWork creativity and productivity suites, as well as professional applications like Final Cut Pro, Logic Pro, Xcode, its online services include the iTunes Store, the iOS App Store, Mac App Store, Apple Music, Apple TV+, iMessage, iCloud. Other services include Apple Store, Genius Bar, AppleCare, Apple Pay, Apple Pay Cash, Apple Card. Apple was founded by Steve Jobs, Steve Wozniak, Ronald Wayne in April 1976 to develop and sell Wozniak's Apple I personal computer, though Wayne sold his share back within 12 days.
It was incorporated as Apple Computer, Inc. in January 1977, sales of its computers, including the Apple II, grew quickly. Within a few years and Wozniak had hired a staff of computer designers and had a production line. Apple went public in 1980 to instant financial success. Over the next few years, Apple shipped new computers featuring innovative graphical user interfaces, such as the original Macintosh in 1984, Apple's marketing advertisements for its products received widespread critical acclaim. However, the high price of its products and limited application library caused problems, as did power struggles between executives. In 1985, Wozniak departed Apple amicably and remained an honorary employee, while Jobs and others resigned to found NeXT; as the market for personal computers expanded and evolved through the 1990s, Apple lost market share to the lower-priced duopoly of Microsoft Windows on Intel PC clones. The board recruited CEO Gil Amelio to what would be a 500-day charge for him to rehabilitate the financially troubled company—reshaping it with layoffs, executive restructuring, product focus.
In 1997, he led Apple to buy NeXT, solving the failed operating system strategy and bringing Jobs back. Jobs pensively regained leadership status, becoming CEO in 2000. Apple swiftly returned to profitability under the revitalizing Think different campaign, as he rebuilt Apple's status by launching the iMac in 1998, opening the retail chain of Apple Stores in 2001, acquiring numerous companies to broaden the software portfolio. In January 2007, Jobs renamed the company Apple Inc. reflecting its shifted focus toward consumer electronics, launched the iPhone to great critical acclaim and financial success. In August 2011, Jobs resigned as CEO due to health complications, Tim Cook became the new CEO. Two months Jobs died, marking the end of an era for the company. Apple is well known for its size and revenues, its worldwide annual revenue totaled $265 billion for the 2018 fiscal year. Apple is the world's largest information technology company by revenue and the world's third-largest mobile phone manufacturer after Samsung and Huawei.
In August 2018, Apple became the first public U. S. company to be valued at over $1 trillion. The company employs 123,000 full-time employees and maintains 504 retail stores in 24 countries as of 2018, it operates the iTunes Store, the world's largest music retailer. As of January 2018, more than 1.3 billion Apple products are in use worldwide. The company has a high level of brand loyalty and is ranked as the world's most valuable brand. However, Apple receives significant criticism regarding the labor practices of its contractors, its environmental practices and unethical business practices, including anti-competitive behavior, as well as the origins of source materials. Apple Computer Company was founded on April 1, 1976, by Steve Jobs, Steve Wozniak, Ronald Wayne; the company's first product is the Apple I, a computer designed and hand-built by Wozniak, first shown to the public at the Homebrew Computer Club. Apple I was sold as a motherboard —a base kit concept which would now not be marketed as a complete personal computer.
The Apple I went on sale in July 1976 and was market-priced at $666.66. Apple Computer, Inc. was incorporated on January 3, 1977, without Wayne, who had left and sold his share of the company back to Jobs and Wozniak for $800 only twelve days after having co-founded Apple. Multimillionaire Mike Markkula provided essential business expertise and funding of $250,000 during the incorporation of Apple. During the first five years of operations revenues grew exponentially, doubling about every four months. Between September 1977 and September 1980, yearly sales grew from $775,000 to $118 million, an average annual growth rate of 533%; the Apple II invented by Wozniak, was introduced on April 16, 1977, at the first West Coast Computer Faire. It differs from its major rivals, the TRS-80 and Commodore PET, because of its character cell-based color graphics and open architecture. While early Apple II models use ordinary cassette tapes as storage devices, they were superseded by the introduction of a 5 1⁄4-inch floppy disk drive and interface called the Disk II.
The Apple II was chosen to be the desktop platform for the first "killer app" of the business world: VisiCalc, a spreadsheet program. VisiCalc created a business market for the Apple II and gave home users an additional reason to buy an Apple II: compatibility with the office. Before VisiCalc, Apple had been a distant third place c